Buried objects detection and classification with a 3-D parametric sonar

Abstract

This paper deals with a new sonar concept suitable for mine detection and classification in shallow and very shallow water. This concept is based on a 3-D high-resolution imaging information obtained from a 2-D scanning. Sediment penetration and narrow-beam constraint is made possible by the use of the parametric technique. A specific tool has been designed to be able to make a connection between a real operational configuration and experimental needs. A 2×2 m2 suspension frame has been built to allow the sonar displacement along the two axis direction. This suspension frame has been deployed first in a pool and then at sea above three different areas where mines and rocks had been buried. Experiments have been conducted in a shallow water area with the suspension frame mounted 2 m above the sea floor made of rough sand. Three-dimensional imaging techniques have been used to process the data and very good results have been obtained. Underwater mine and object detection and shape classification have been successfully demonstrated up to half a meter sediment burial. This paper shows these first results and describes sonar and signal characteristics and then discusses the data and image processing.